Here is a minimal example for PyQt4, to set up a main window and connect a simple action to some slot. The documentation on doing this is sparse to say the least. So I hope this is helpful for anyone trying something similar. I assume that you have created a ui_MainWindow.ui file with Qt Designer, which contains a form derived from QMainWindow.
from PyQt4 import QtCore, QtGui, uic
self.ui = uic.loadUi("ui_MainWindow.ui", self)
self.connect(self.ui.actionOpen, QtCore.SIGNAL('triggered()'), self, QtCore.SLOT('open()'))
fileDialog = QtGui.QFileDialog(self, "Open file")
app = QtGui.QApplication(sys.argv)
mainWindow = MyMainWindow()
I really don’t get happy with Qt 4.6 on OS X 10.6. Nokia rates Qt on that platform as Tier 2. Which means, it is not fully supported. This results in stupid things happening. With Licq, I currently have the problem that the whole program crashes with the following message:
+[NSUndoManager(NSInternal) _endTopLevelGroupings] is only safe to invoke on the main thread.
The problem here is that Qt 4.6 for 64 Bit is (rightly so) built using the Cocoa API, instead of the C-only Carbon API. Now it seems that Qt uses the NSUndoManager
, which in turn has an undocumented (?) function _endTopLevelGroupings. And as the above mentioned message tells you, it is only safe to call that function from the main thread. Since the qt4-gui plugin of Licq runs in a separate thread, this assertion fails, and the whole program crashes. So this basically means you cannot start up your GUI from a secondary thread with Cocoa based Qt. This, I think, constitutes a bug in Qt.
: I submitted a bug tracker item
, and erijo is producing a minimal example that will hopefully show the bug in action. Now let’s wait and see.
Good news: The Qt port of MacPorts is working again. The port was upgraded to Qt 4.6 and now it compiles again. Now all I need is a 64 bit CUDA package for Snow Leopard, and I’ll be happy.
This allows you to convert any preprocessor macro value to a string, e.g. for printing.
#define MEINMAKRO 1.3.4
#define STRINGIFY(x) #x
#define TOSTRING(x) STRINGIFY(x)
std::cout << TOSTRING(MEINMAKRO) << std::endl;
Since several people asked me how to do this, after I twittered
about this, here it comes: How to correctly sync the Google Calendar with the iPhone. First step is to create a new calendar account in the iPhone settings (Email, Calendar, Contacts) using the Exchange protocol. The finished account should look something like this:
You can also sync the contacts and emails, if you want, but that’s optional. The second step is to go to http://m.google.com/sync/
to set up which of your google calendars you are going to sync. Beware: on the german iPhones, the page will display an error message, unless you switch to the english page!
That seems to be a bug on google’s page. So after you’ve done this, you get a list of your iPhones and can select for each device which calendars to sync:
I am using the try-out version of Mobile Me for the iPhone. Syncing the device with the Macbook Pro. Whenever I go to my address book, all the contacts appear twice. Very strange, I though, until I noticed that I was in the Group “All contacts”, which will show the contacts synced from the Mac and from Mobile Me. What a stupid way to present things. Right now, I just need to switch to “All contacts from my Mac” to fix this, but when I were to add another address book (say a corporate one or the Google one), I would be in trouble. Not very clever, Apple…
Oh dear, Nokia and Macports do seem to hate me. I’ve spent half a day to get some version of Qt running on OS X 10.6.2. The problem is as follows. Nokia only provides 32 bit builds of their Qt SDK for OS X (universal binaries for PPC and i386) as can be seen here and here. Under OS X 10.5 this was no problem, since the whole system was basically 32 bit. But Snow Leopard now builds for x86_64 per default. Especially when using Macports. So I thought, lets just install the qt4-mac port from Macports. Wrong again! That port is currently broken. So, my project depends half on Qt and half on stuff from Macports. Now neither one is in a usable state. Ok, so I thought maybe I can force Macports to build in i386 mode only, to be compatible again with Qt. So I edited /opt/local/etc/macports.conf, cleaned the whole Macports tree and reinstalled. Fail again. This time, perl5 fails to build. That port is broken on 10.6 for non 64 bit builds. Hooray. Well, I give up for today, but will continue to investigate and will report back, as soon as either Nokia provides a decent 64 bit build, or Macports recovers and fixes any of their build issues.
After my upgrade to OpenSUSE 11.2, I noticed that VLC was again stuttering when playing videos. A quick check revealed, that the upgrade re-installed the PulseAudio system. Removing all Pulse related stuff fixed the problem. I wonder why, oh why on earth all the sound servers under Linux suck? And why are they default for every installation, if they don’t work as expected? I still own a nice SoundBlaster Live, which does sound mixing in hardware, which means I do not even need a sound server, since the card can expect many different audio streams from many applications. Anyway, please, dear sound server developers: If you need to write such a beast of a tool, make it work as expected!
I just upgraded my home machine to OpenSUSE 11.2, and needed a few programs from secondary repositories. SUSE comes with those nice YMP URLs, which allow one-click installation of programs. However, after my change to using sudo from a few weeks back, this does not work anymore. The One Click Installer does not seem to be compatible with sudo yet. So I now found a workaround, by just using the shell to do the same. E.g. if you wanted to install Amarok 2.2, which does not come with SUSE 11.2, you would do:
Nice, isn’t it?